Starting device for explosion and other engines.



W. l. E. B'EERE.

STARTING DEVICE FOR EXPLOSION AND OIHER EBGINES.

APPLICATION FILEDSEPT. Z1, ISIS.

Patented Oct. 29, 191&

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UNITED STATES PATENT OFFICE.

WILLIAM JAMES EDWARD BEERE, OF LONDON, ENGLAND. ASSIGNOR T0 RUSHMORES LIMITED, OF LONDON, ENGLAND.

Specification of Letters Patent.

Patented Oct. 29, 1915.

Application filed September 21. 1915. Serial No. 51,790.

To all whom, it may concern:

Be it known that l, \Vinumu JAMES En- WAIH) Bl'ltlltl'l, a subject. of the King of Eng land, residing in London, England. have in vented certain new and useful Improvements in Starting Devices for Explosion and other Engines, of which the following is a specification.

This invention relates to engine starting devices, and in particular when employed upon motor-cars. of the kind in which the armature of an electric motor. normally out of driving engagement with the engine, is shifted endwise by electromagnetic means to establish driving engagement between it and the engine for the purpose oi starting the engine, and is automatically thrown out of driving engagement when the engine has be gun to be revolved by its own power.

Some starters of the kind referred to have the disadvantage that the motor is caused to rotate before the driving connection between it and the engine is established, and moreover of permitting the supply of current to the motor to he maintained after the latter has been disconnected from the engine. with the result that the motor then attains an undesirable speed of rotation. It is an object of the present invention to provide against the motor being revolved before it is in driving engagement with the engine and against current being supplied to revolve the motor after such engagement has been interrupted.

According to the present invention, in an engine starter of the kind described, means are employed, operated by the endwise shift of the armature, to prevent operative current from passing through the armature unless it is in driving connection with the engine. The means employed to prevent current passing through the armature may either be such as to open-circuit the armature or to short-circuit it; in the former case. the means may take the form of a sleeve of insulating material upon the commutator and, in tin latter case, they may conveniently take the fo m of a conductor supported upon the commutator, but insulated therefrom and adapted to provide a bridging path between the brushes while the armature is in the nonengaged position.

In order to prevent undesired maintenance of driving connection between the starter and engine, or the reestablishment thereof after it has been automatically interrupted,

it is preferred to employ a series sel fn1ain t'aining relay in the motor circuit, and, preferably, a switch to operate the relay so constructed that it is automatically tripped. if its handle is moved home. The relay is preferably constructed to open its circuit at a predetermined minimum current so as to constitute a minimum cut-out.

Further novel details of construction of the switch for cooperation with the relay are hereinafter described and pointed out in the claims.

in the accompanying drawings- Figure 1 is a diagrammatic illustration of one construction of starter in which the circuit between the brushes is open when the armature is in the disengaged position,

Fig. 2 is a. similar illustration of a modification, in which the brushes are connected together while the armature is in the disengaged position. together with a. relay and tripping push button, and

Fig. 3 is a diagrammatic end elevation of part of the switch employed in the arrangement shown in Fig. 1.

In the construction shown in Fig. 1 a series motor is provided whose armature A is slidable axially through its bearings against the thrust of a return spring B. On one end of the armature spindle is mounted a pinion 0 adapted to engage with teeth upon the engine fly-whcel D, but normally held out of engagement therewith by the spring B when the latter is free. to assert itself. At the commutator end of the motor is a circuit closer in the form of two spring contacts E, E, which are normally open but which are closed by the coned outer periphery F, of a short sleeve F, mounted upon ball hearings on the armature shaft so as to rotate relatively to it. but so as to move axially with the shaft.

Energy is delivered from a battery G through a three-way switch H whose first contact H is dead, whose second contact H is connected through a resistance J to the point of junction of the field windings A, of the motor with one brush, and whose third contact H is connected to the free member of the pair E, 131,; the other member of this pair is connected to the other brush. The movable arm of the switch is spring-controlled so as always to return to the contact H, when left to itself.

A dog H is pivotally hung from the underside of the arm H, as seen in Fig.

The dog is insulated from the arm and the latter is of sulliciently springy construction or mounting to allow the dog,.by its engagement with the edge of the contact PL, to lift the arm clca r of that contact on the return movement. The switch base is cut away at H, to allow the (log to hang free between. the contacts H and H To start the engine the switch is first moved on to the contacts H, whereupon the field magnets alone of the motor a'rc energized and these draw the armature endwise against the thrust of the spring B to cause the teeth of the pinion C to cmnesh with the teeth on D. The teeth of the pinion and of the fly-wheel are pointed on their opposed ends to promote enmeshment. If enmerhment has duly occurred the spring contacts E, E, are closed but the sleeve F is so placed on the armature shaft that until enmesle ment has occurred these contacts remain open.

If enmeslnnent has occurred and the switch arm is then moved on to the contact. H the armature will receive current through E, E, and will start the engine. Then the engine fires and drives the motor, the back clcctro-motive force generated in the armature cuts down the current flowing through the motor to a value at which the field magnet can no longer overcome the spring B. This, therefore begins to return the armature toward the position shown in Fig. 1, but before disen agement from the fly-wheel has occurred, t e motor circuit is broken at E, E This leaves the spring unresisted by any n'iagnetic pull so that it completes the disengagement of the armature pinion from the fly-wheel smartly and with certainty. The operator then releases the switch arm H and this flies back on to the contact H passing over the contact H, without touching it, owing to. the action of the trip-dog H Should the pinion and fly-wheel fail to enga 'e when the switch arm is put on to corn tact TL, and the arm be thcn movcd on to the contact H the circuit is broken and the armature slides back into the position shown in Fig. 1 withoutany ill efi'ect; the operation is then repeated.

In the arrangement shown in Fig. 2 a sleeve of metal K is mounted upon the commutator, but so as to be insulated from it, and the sleeve is so dimensioned that when the armature is in the disengaged position a bridging circuit is provided by the sleeve from brush to brush. At L is a relay upon which are two windings namely L hereinafter referred to as the operating winding, and L hereinafter referred to as the series winding. The former is energized from the battery G through a push-button M, the details of whose construction are shown in diagram in Fig. 2. The series winding L is energized only when the relay contact is closed under which condition current flows from the battery through the series winding and the relay contact in series; this Contact is shown at The relay is therefore of the 'selfinutintaining type, that is to Say, when it has been energized by means of the operating coil i it maintains its own con tact closed by the current which flows through that contact. A pull-otl' spring L serves to open the contact when the current in the winding L, falls to a predetermined lower value; in this way the relay operates as an automatic minimum cutout.

The pnslrhutton is constructed with a sliding contact piece, M and a fixed contact piece L1,. The former is normally in conducting contact with two dctents M each of which is carried upon a springy limb O of the push piccc R. Each of these limbs carries at its lower extremity a tapered projection 0, adapted to enter a conical recess hit, in the center of the lower contact piece M, Springs I tend to hold the contact piece M, in the upper position in which it is seen in Fig. 5'! and a flexible connector Q is provided; winner-ted in any convenient manner to a leading in wire Above the detents ll, the limbs (l are sheathed with insuiating material to prevent contact between them and the sliding piece M at this art of their length. A lead Q is connecte to the contact M In operation, when the push-piece R is pressed down the piece M is carried down with the limbs against the tension of the springs P, and when contact occurs between the pieces and the piece M current flows from the leading-in wire Q, through the flexible connector Q. the niece M, the limbs O and the contacts 0,, Iv 2 to the lead wire (3,. As, however, the movement is continned, by the piece R being pushed home, the limbs approach one another owing to the cooperation of the recess M, with the projections and thus disenga e the detents M7 from the piece M he latter thereupon snaps back into its normal position under the action of the springs P and so breaks the circuit through the button, which may be said now to be tripped.

The e [feet of the circuit through the push button being closed is to energize the operating coil L, of the relay; this closes its contract L, and the battery G thereupon sends current throu h the windin L the contact L the sleeve and the field windings A of the motor. \Vhen. therefore, the push-button is tripped by being pushed home, the relay maintains its own contact closed, although the operating circuit is now dead. \Vhen the armature is pulled into engage ment with the flywheel it brings the commutator beneath the brushes and receives operative current to rotate it. This action is gradual though rapid, since for a portion of the cndwisc movement of the. armature the brushes bear both upon the commutator and upon the sleeve K. No contact is, however, made with the commutator until after the pinion on the armature spindle has been brought into engagement with the teeth on the fly-wheel.

VVhcu the engine tires, the current is reduced to such a value that the relay acts as a minimum rub-unit and releases its armature; the motor armature is then returned into the disengaged po i on by the spring automatiralla: whether or no the push button is held on inegiigr-nzi or has been released, as it. shouhi lune been, by the operator. In effect, the ron traction of the puslrbulton and relay trans ti-rs from the operator to the relay the dntv oi lice 'iing current on to the motor and the: relay discharges its function automaticallv. so that current is not kept on longer than drrirahk. irrespective of negligame on the part of the operator. It will be understood that with an ordinary push-bub ten or switch, it the operator heid it closed after the engine had fired, the armature would be thrown back into the engaging position after having become disengaged, which is highly undesirable, and would probably mean destruction of the teeth on the pinion or iiy-whccl, or both.

The above described constructions are given by way of example, only, and other constructions which prevent operative current traversing the armature t rotate it when i is not. in driving engagcuu-nt with the mtg-"inn, within the" MHfw (I? illlF lib vrntiuu.

i or example, he slee e K may be a sleeve oi in ulating material. Furthermore, other o ructions of push-buftim or switch any to 1;, be devised to be automatically tripped when moved home into the full-on position and such other onstructions of push-button or switch when lob." used for the purpo e ln-reiuhofore described, fall within the scope of 1his invention.

'hat l claim as my invention and desire to secure by Letters Patent is:-

I. In an engine-starter. the combination of a motor whose, armature is norn'ially out of driving engagement with the engine but is elm-lro-magnetirally shifted endwise to establish the said driving engagement. a body carried upon the ronnnulator and so situated thereon as to lie engaged between the brushes of the motor while the armature is in the non-engaged position and prevent operative current traversing the armature windings from brush to brush but. of such dinu-nsiou iu the direction of said endwisrmovement a to be brought out of coin tact with the bru hes when the armature is in the engaged position. and means eontrollod |i the vlm'lln-lllflllH' force generated in the motor when the engine is accelerated by its own power whereby the supply of current to the motor is auton'iatically interrupted.

2. In an engine starter the combination of, a motor whose armature is normally out of driving engagement with the engine but is clectro-magnetically shifted cndwise to establish the said driving engagement. mean adapted to short circuit the brushes of the motor while the armature is in the non-engaged position but to open the said short-circuit when the armature is in the engaged position, and means controlled by the electro-motive force generated in the motor when the engine. is accelerated by its own power whereby the supply of current to the. motor is automaticall interrupted.

3. In an engine starter the combination of, a motor whose armature is normally out of driving engagement with the engine but is elcctromagnetically shifted cndwisc to establish the said driving engagement, means operated by the endwisc shift of the armature to prevent operative current from passing through the armature to rotate it unless it is in driving connection with the engine, including a conductor supported upon the commutator but insulated therefrom and supported in such a position that it short'eircuits the motor brushes while the armature is in the non-engaged position but breaks its connection with the brushes when the armature is in the engaged position, means controlled by the electromotive force generated in the motor when the engine is accelerated by its own power, whereby the supply of current to the motor is automatically interrupted.

4'. In an engine starter the combination oi, an electric motor which normally is out. of driving engagement with the engine, electro-magnetic means to establish driving engagement between the motor and the en gine, means controlled by the aforesaid means to prevent current effective to rotate. the armature being supplied to the armature unless the said driving engagement is operative, and a relay of the series self-maintaining type in the supply circuit to the motor the said relay having its operating circuit controlled by a switch \Vlllt'll is auto-- matically tripped when its handle is moved into the full on position.

5. In an engine starter the combination of, an electric motor which normally is out of driving engagement with the engine, elect ro-magnetic means to establish driving engagement between the motor and the engine, means controlled by the aforesaid means to prevent current etlective to rotate the armature being supplied to the armature unless the said driving engagement is opel ative, and a relay of the series self-unlintainiug type in the supply circuit to the motor, the said relay having its operating circuit controlled by a switch having a circuit closing member and handle therefor so constructed that when the handle is moved home in the circuit closing position the said circuit closing member is mechanically tripped from its engagement with the handle and moves into the open circuit position.

6. In an engine starter the combination of, an electric motor which normally is out of driving engagement with the engine, electro-Inagnetic means to establish driving engagement between the motor and the en gine, means controlled by the aforesaid means to prevent current effective to rotate the armature being supplied to the armature unless the said driving engagement is operative, and a relay of the series self-maintaining type in the supply circuit to the motor the said relay having its operating circuit controlled by a switch having a circuit closing member and handle therefor and a detent to connectthe said circuit closing member with said handle which detent while the circuit closing member is in the circuit closing position is automatically displaced to disengage the said member from the handle.

In testimony whereof I have signed my name to this specification in the presence of two subscribing Witnesses.

WILLIAM JAMES EDWARD BEERE.

Witnesses:

HARRY B. GRIDGE, JAMES MIDDLETON. 

